Get Interface IP Addresses

GetInterfaceAdresses.swift

// https://ja.stackoverflow.com/questions/60182/swift-ip%E3%82%A2%E3%83%89%E3%83%AC%E3%82%B9%E3%81%AE%E5%8F%96%E5%BE%97%E6%96%B9%E6%B3%95%E3%81%A8%E3%83%96%E3%83%AA%E3%83%83%E3%82%B8%E3%83%B3%E3%82%B0%E3%83%98%E3%83%83%E3%83%80%E3%81%AB%E3%81%A4%E3%81%84%E3%81%A6
func getInterfaceAddresses() -> [String: String] {
    var first: UnsafeMutablePointer<ifaddrs>?
    guard getifaddrs(&first) == 0,
          let firstAddrs = first else { return [:] }
    defer { freeifaddrs(first) }

    var addresses: [String: String] = [:]

    for current in sequence(first: firstAddrs, next: \.pointee.ifa_next) {
        let addressFamily = current.pointee.ifa_addr.pointee.sa_family
        if addressFamily == UInt8(AF_INET) || addressFamily == UInt8(AF_INET6) {
            var address = current.pointee.ifa_addr.pointee
            var addressChars: [CChar] = Array(repeating: .zero, count: Int(NI_MAXHOST))

            getnameinfo(&address, socklen_t(address.sa_len),
                        &addressChars, socklen_t(addressChars.count),
                        nil, 0,
                        NI_NUMERICHOST)

            let interfaceName = String(cString: current.pointee.ifa_name)
            addresses[interfaceName] = String(cString: addressChars)
        }
    }

    return addresses
}